Phone number recognition

ABSTRACT

Method and system for recognising a numeric or alphanumeric sequence of characters in a document, the sequence conforming to predetermined rules and representing user identifiers for identifying users in a communication system include identifying a country of origin of the document, recalling rules relating to the format of the sequence associated with the determined country of origin, searching the document to identify any sequence in the document satisfying the format and returning any such sequence.

FIELD OF THE INVENTION

The present invention relates to a system and method for phone numberrecognition. The phrase “phone number” encompasses any numerical oralphanumeric sequences which can be used to instigate a communicationbetween two end-users and includes within its ambit fax numbers.

BACKGROUND OF THE INVENTION

The primary purpose of phone number recognition components is torecognise a phone number in a piece of text and identify it as such.Further enhancements include being able to use that phone number to makea call, which may involve cleaning up the format of the recognised phonenumber to put it into a proper format taking into account country codesetc to be able to make the call. Phone number recognition can be used inthe context of a peer to peer telephone system of the type described inWO 2005/009019. In this system, a plurality of end users can beconnected for communication purposes via a communications structure. Thecommunications structure is substantially decentralised with regard tocommunication route switching therein for connecting the end users. Thatis, the end users can establish their own communication routes throughthe structure based on exchange of one or more authorisationcertificates (user identity certificates—UIC) to acquire access to thestructure. The structure includes an administration arrangement issuingthe certificates to the end users. One such phone system exists underthe trade name SKYPE (™).

Phone number recognition can be used in other contexts. Automatedrecognition of phone numbers in a piece of text is not a simple matter.The text may include various numerical or alphanumeric sequences whichare not phone or fax numbers. It is important that any automated phonenumber recognition component is capable of correctly identifying onlyphone numbers. Moreover, if the phone number is to be used for calling,it is necessary to further identify the location of the caller, thelocation of the phone number to be called and the necessary countrycodings to be used to put the phone number into a proper format formaking a call.

SUMMARY OF INVENTION

According to an aspect of the present invention there is provided amethod of recognising a numeric or alphanumeric sequence of charactersin a document, said sequence conforming to predetermined rules, andrepresenting user identifiers for identifying users in a communicationssystem, the method comprising identifying a country of origin of thedocument; recalling rules relating to the format of said sequenceassociated with the determined country of origin; searching the documentto identify any sequence in the document satisfying said format; andreturning any such sequence.

The document can be a any text, for example a web page located by a webbrowser on the world wide web, an Office document, an email or a PDFfile etc.

Another aspect of the invention provides a method of initiating acommunication via a communication network, the method comprising:marking in a document at least one sequence representing a communicationidentifier, the step of marking comprising associating said identifierwith a button displayed to a user; actuating the button at a userinterface of a user terminal; and executing a client installed at theuser terminal to receive said identifier and instigate the communicationvia the communication network using the identifier.

A further aspect of the invention provides a system for recognising anumeric or alphanumeric sequence of characters in a document, saidsequence conforming to predetermined rules and representing useridentifiers for identifying users in a communications system, the systemcomprising a component for identifying a country of origin of thedocument: a store holding rules relating to the format of said sequenceassociated with the different countries; a search component arranged tosearch the document to identify any sequence in the document satisfyinga format for the determined country of origin; and a tool forinstantiating an object for returning any such sequence.

A still further aspect of the invention provides a computer readablemedium comprising computer code components which, when executed by acomputer into which the computer medium is installed, implement thefollowing method steps: identifying a country of origin of a document;recalling rules relating to the format of a sequence of numeric oralphanumeric characters associated with the determined country oforigin; searching the document to identify any sequence in the documentsatisfying said format; and returning any such sequence.

A still further aspect of the invention provides a method of effecting avoice communication between user terminals over a communication network,the method comprising: displaying to a user at a user interface a menuof country options: selecting a country of a destination of thecommunication from said country options; receiving a number in localform; recalling formatting rules for the destination country; appendingto the number a country prefix for the country of destination inaccordance with the formatting rules to generate a formatted number; andsupplying the formatted number to a client installed at the userterminal for effecting the voice communication using the formattednumber.

In embodiments of the invention, the cost per minute of a call to thatphone number can be worked out. Moreover, it can be identified if thephone number is a mobile number.

For a better understanding of the present invention and to show how thesame may be carried into effect, reference will now be made by way ofexample to the accompanying drawings, in which:

FIG. 1 is a schematic block diagram of elements associated with a phonenumber recognition (PNR) component:

FIGS. 2 to 4 are screen prints showing operation of a toolbar with thePNR components;

FIG. 5 is a schematic block diagram of components on a user terminal,such as a personal computer;

FIG. 6 is table illustrating a country object;

FIG. 7 is a flow chart illustrating in overview the operation of the PNRcomponent;

FIG. 8 illustrates a computer system with the click to callfunctionality; and

FIG. 9 shows a display for selecting countries.

DETAILED DESCRIPTION

The invention will be described in the context of a peer-to-peertelephone system of the type described in WO2005/009019. However, itwill readily be appreciated that the phone number recognition componentdescribed herein can be used in any other context where it is useful torecognise and utilise phone numbers in text (or an image). For example,the phone number recognition component could be used to identify phonenumbers in emails or in a list of members or attendees of anorganisation.

To implement a peer-to-peer telephone system, client software 300 formaking calls is downloaded onto end users' personal computers (PCs) toallow the end users to communicate via the decentralised communicationsstructure such as the Internet or world wide web. The client software isnot the subject of this invention and so is not described herein, but itis capable of receiving a phone number for an end user in a standardisedformat and implementing a call to that user. It also has a registry forholding user names and numbers, so that a name, instead of a number, canbe used to instigate a call. Toolbars associated with the clientsoftware include a phone number recognition component. FIG. 1illustrates a phone number recognition component to be launched forexample on a toolbar associated with a peer to peer telephone system.The phone number recognition component 2 comprises a program which isexecuted by the PC when it is launched and which cooperates with anumber of elements to generate as an output a collection of phonenumbers.

An input element 4 provides a set of inputs including a text to searchinput 6, a domain input 8, a default country prefix 10, an html-Booleaninput 12, an asynchronous-Boolean input 14 and a secondary domain 16.

A data element 18 provides data items to the phone number recognitioncomponent 2 in the form of a table (FIG. 6) including for each region acountry name 20, minimum digits for an area code 22, maximum digits foran area code 24, minimum digits for a subscriber number 26, maximumdigits for a subscriber number 28, domain 30, characters to remove 32,only digit data item 34, period allowed 36 and an always starting digit38. The data element 18 also provides read settings from XML web service40, language recognition 42, fax number strings 44, fax and phonestrings 46, carriers 48, rates 50 and rate for country 52.

A procedures element 54 provides the following procedures:

-   -   language 56,    -   GEO zones 58,    -   countries 60,    -   default country 62,    -   country by ISO code 64,    -   current prefixes 66,    -   country from string 68,    -   country selector dialling 70.

A phone number rules element 72 provides phone number pattern 74,allowed character 76, SKYPE (™) names 78, number in hyperlinks 80,patterns that are not phone numbers 82, US phone numbers 84, US telenames 86, starting digits 88.

The phone number recognition component 2 includes an output element 90which returns a collection of located numbers 92. The numbers have a setof class properties returned in a number class phone object 100 asfollows:

-   -   verified 102,    -   length 104,    -   name 106,    -   type (SKYPE out or SKYPE call) 108,    -   position 110,    -   number to display 112,    -   number to call 114,    -   tool tip property 116,    -   rate 118,    -   is fax only 120,    -   is fax 122,    -   is mobile 124.

Before discussing the above individual elements in detail, the generalfunctionality of the phone number recognition component will bedescribed. FIG. 2 is a screen print showing the SKYPE (™) page andspecifically a toolbar 200 which provides a SKYPE button 202, a countrysearch button 204, a search domain 206 with an associated search field208 and a country code button 210.

The SKYPE button 202 provides a menu of options connected with operationof call functionality associated with SKYPE. These are not germane tothe present invention and are not discussed further herein.

The country search button 204 provides a menu of options as follows:

-   -   United Kingdom    -   United States    -   Country Search.

The country search facility will be discussed later in connection withthe procedures elements 54. The country code button 210 is likewiselinked to a country search facility which will be discussed later. Thesearch domain 206 and search field 208 are not germane to the inventionand are not discussed further here. Note that the country code andcountry search buttons have defaulted to a phone code +1. The default isthe country of registration of Windows software if installed on thecomputer.

The toolbar 200 forms part of a conventional toolbar 212 of a knownworld wide web explorer such as Microsoft Internet Explorer. Thattoolbar includes a field 214 for receiving a web address, by means ofwhich a web page can be accessed using a web browser executed on the PC.

FIG. 3 shows the effect of entering a website address into the field 214of the main toolbar 212, in this case http://www.pagewhite.co.uk/. Thisbrings up the web page for the firm of European patent attorneys PageWhite & Farrer. On the home page for the website of Page White & Farrerthere are no detectable telephone numbers, but the county of origin ofthe page is detected as UK, so that the country code button 210 changesto +44 Navigating through the Page White & Farrer website, in particularby clicking on the people icon and selecting one of the directors, leadsto a page on which there is an identifiable telephone number 216 asshown in FIG. 4 The detection of the telephone number 216 by the phonenumber recognition component has a number of effects. The country codebutton 210 is automatically changed to the country code reflected in thedetected telephone number. In this case +44 for GB. A call button 218 isinserted into the web page. In addition, a country logo/flag 220 isinserted indicating the corresponding country for the phone number inthis case Great Britain.

If a user activates the call button 218, then a call is instigatedthrough the peer to peer telephone system. This is done by transferringthe number to call property 114 of the number class phone object 100(forming part of the output elements 90) to the local client software300. By using the input elements 4, data elements 18, procedure elements54 and phone number rules 72 in a manner to be described more fullylater, the number to call property 114 provides the phone number in aformat which can be called by the client software 300 without furthermodification FIG. 5 is a schematic block diagram of components on a userPC which are used with the phone number recognition component 2. The setof inputs 4 are provided from a web browser 302 to the toolbar 304 andfrom these to the PNR component 2. The inputs will now be discussed inmore detail.

The text to search 6 is input from the web browser 302 and can be in anytext format e.g. Unicode, html.

The domain input 8 picks up the domain from the website (e.g. .com, .uk,.se) and if a domain name is specified the PNR component 2 will searchin the text only for phone numbers that are in a specified format forthe country represented by that domain. The formats are provided in thetable in the data elements 18.

A default country prefix 10 can be specified by a user using the countrycode button 210 to override any automated country identification. If thedefault country prefix 10 is supplied, only phone numbers are searchedwhich if appended with the prefix would form valid phone numbersaccording to the phone number rules 72.

The html-Boolean input 12 is set in the toolbar if the text to besearched from the web browser is a html page. In that case, the PNRcomponent 2 searches to see if there is a metatag in the header of thepage which identifies the content as SKYPE toolbar parser compatible:<metaname=“SKYPE_TOOLBAR” content=“SKYPE_TOOLBAR_PARSER_COMPATIBLE”/>

In that case, the text is only parsed for particular constructs asdefined below: <!-- sphoneid telnr=“+15551234456” fileaz=“John Smith”--> (555) 1234 456 <!-- sphoneid -->.

An asynchronous (Boolean) input 14 is set in the toolbar to indicatewhether the client software 300 wants to wait for parsing to be done orfor the result to be raised as an event.

A secondary domain 16 can be set. A secondary domain is relevant in thecontext of shared domains. A shared domain is a domain of the world wideweb which is not clearly identified as specific to a single country, forexample .com, .tv, .nu, .net, .travel, .eu.

If the secondary domain input is specified, the toolbar dispatches twoparameters to the SKYPE toolbar 200 as the default domain, the localedomain and the shared domain. The locale domain is taken from localsearch partners which are displayed (field 206, 208) for a specifiedcountry. This information is used as an additional clue when guessing atwhich country might be appropriate for the current web page. In thatcase, the toolbar 200 supplies the PNR component 2 with both the shareddomain and the local domain. In this case, the PNR component wouldsearch for phone numbers in the local format in the current page, andreturn those in the same collection as the phone numbers for the shareddomain page (which are searched without format restrictions).

The data elements 18 are held in an XML file or other resource 304. Thedata will now be described in more detail.

The country name 20 is the name of the country for which the informationapplies. The data is held in the form of a table (see FIG. 6) having alist of countries and the data element 22 to 38 associated with eachcountry. This list is also localized in 27 languages. The area codeminimum digits 22 is the minimum number of digits allowed in an areacode for the country. The area code maximum digits 24 is the maximumnumber of digits allowed for an area code in the country. Subscriberminimum digits 26 is the minimum number of digits in a subscriber numberfor that country. The subscriber maximum digits 28 is the maximum numberof digits in the subscriber number for that country. The domain 30 isthe domain name that goes with that country (for example .se forSweden).

Characters to remove 32 represents a character (usually zero) which isremoved when calling internationally.

The only digits data item 34 is a Boolean property which indicateswhether only digits are allowed in the phone number. For example USphone numbers are never written like this: +15551231234. Even though itis the correct number of digits it would not be picked up, since itdoesn't have any spaces, parenthesis etc.

The period allowed data item 36 is a Boolean value indicating where theperiods are allowed as characters within a phone number for the country.

The always starting digit data item 38 is a Boolean value indicatingwhere the phone numbers for this country should always start with thecharacter which will subsequently be removed, in order to make aproperly formatted number.

Although included as part of the data elements 18, the read settingsfrom XML web service 40 is in fact a code sequence which allows the PNRcomponent 2 to check for updates from a web server periodically. Thisallows as much as possible of the data to be stored on a web server sothat patterns and, rules can be improved without having to update thelocal PNR component.

The language recognition data item 42 is a list of phrases which can beused to uniquely identify a text as being from a specific language. Forexample, for English the phrases could be “and” and “the”. In German,the phrases could be “und” and “das”.

The fax number strings data item 44 is a property “is fax only” which isset to true if the PNR component 2 determines that a phone number is afax number. It does this by checking the text that comes immediatelybefore the phone number or in the previous html table cell. If that textis one of the following strings in any language, then the new property“is fax only” is set to true, and an associated property “is fax” isalso set to true. Both these values are set false by default.

Fax, telefax, fax number, telefax number.

The fax and phone strings data item 46 is similar in order to identify anumber which is for use both as a fax and telephone number. In this casethe phrases are fax/tel, telephone and telefax, fax and tel, fax&tel,tel&fax, tel and fax.

If one of these is found, the “is fax only” property should be set tofalse but the “is fax” property should be sent to true.

The carriers data item 48 is a list of all mobile carriers.

The rates data item 50 is a list of the rates for each carrier. Thislist can be used to determine the rate for a particular phone number. Ifthe rates are stored on the web server, the read settings component 40should update them periodically.

The rate for country data item 52 is able to display an appropriatecurrency for each country.

Reference will now be made to the procedures element 54. The procedureselement 54 holds a number of elements which are utilised to determinethe most likely country of the web page in which the phone number is tobe recognised. These procedures are implemented in the PNR component.

The language procedure 56 allows a default setting language to beobtained from a registry setting within the client software.

The GEO zones collection 58 contains a countries collection 58 a whichin turn contains country objects 58 b with associated flag objects 58 c.The country objects expose domain, prefix, phone number, length etc asin the table of FIG. 6. In addition, it gives the localised country namebased on the current language setting.

The default country element 62 is a country object that has the sameproperties as the country object 58 b. It can be read from the Windowsregistry setting of the PC and compared to the available list ofcountries, just in case the user might have Windows set to some countrywhich is not in the list of PNR countries.

The country by ISO code 64 is a property of the country object whichidentifies the country by its ISO code.

The current prefixes element 64 is a property which returns an array ofprefixes, properly prioritised. Again, this is for the shared domainscenarios. If a page is .com the Current Prefixes identify which countrycodes have been found in the current page. Currently only the first isused in the web toolbars, but the collection could be used to givesecond and third guesses also. The current prefix property is returnedfrom the input elements 4 and procedures elements 54 using the followingpriorities:

-   -   1. Page language (procedures element 56)—if unique to one        country, both if recognised by html language code and if        recognised by language recogniser. Inside html the correct        language can specified with a special html tag (language code).        If this is not properly done, the PNR component runs a language        recogniser component which tries to determine which language the        text is written in (for some languages). In some cases that        gives a clue as to which phone numbers might be written on the        current page.    -   2. Primary domain (input element 8)—if unique to one country.    -   3. Prefix (input element 10)—if supplied as a parse parameter.    -   4. Secondary domain (input element 16)—if supplied as a parse        parameter.    -   5. SKYPE language (from procedures element 56)—if unique to one        country

Skype language is used as an additional clue as to what country thecurrent page belongs to. When a client is installed to implementpeer-to-peer calling, e.g. Skype, a language setting is used todetermine the language of the user. If all the above fails then theSkype language setting is checked. If Skype is in Swedish for example itis more likely that a visit is to a Swedish .com site than to a Japanesesite and vice versa.

The following are examples of how the current prefix property will bereturned.

EXAMPLE 1

A user with Swedish locale browse and SKYPE set to Swedish to the pagewww.datorbutiken.com, which does not have any language set in the htmlsource.

In this case the Current Prefixes property should return:

Prefix(0)=1

Prefix(1)=46

EXAMPLE 2

A user with Swedish locale browse and SKYPE set to Swedish to the pagehttp://phonebook.livedoor.com/search/?lowflg=1&prefcd=13&typecd=3108000which does have Japanese setting in the html source.

In this case the Current Prefixes property should return:

Prefix(0)=81

Prefix(1)=46

Prefix(2)=1

Note that 46 is the country code for Sweden, 81 is the country code forJapan and 1 is the country code for the USA (most likely country codefor universal or shared domains).

Country from string element 68 finds the country for a specific countryname. For example, if the string “Sverige” or “Schweden” is supplied, itreturns the country object for Sweden.

Country selector dialogue element 70 uses a map interface for settingthe locale if the user wishes to override the locale determined by anythe procedures. This uses a map as in FIG. 9 which has drop-down menusfor each continent.

The phone number rules 72 are held in an XML file forming part of thePNR component 2. The phone number rules are set up to allow phonenumbers to be recognised in the text which is input to the PNR component2 for searching. If the same number is found multiple times on the samepage, only the first occurring instance is returned in the outputcollection 90.

The following rules are held.

The other phone number patterns rule 74 indicates that the followingformats should be accepted and interpreted as a +33 phone number,removing the zero within parentheses.

33(0)155013660.

The allowed characters rule 76 indicates that a phone number to berecognised on a page can contain the following characters (, ), /, \,space, dot.

If the text being searched is in html format, the text can also containline breaks and carriage returns. In non-html, those characters cannever be part of a phone number but in html they can. Any othercharacters inside a number sequence means that this is not a phonenumber or it is the end of a phone number sequence and the numbersbefore that should be compared to the rule for the current country.

The SKYPE names rule 78 allows the PNR component 2 to locate call to ://links within the supplied text. These are returned in the phone numberclass object 100.

The number in hyperlinks rule 80 allows numbers which are not phonenumbers but which are located in hyperlinks to be filtered out.

The patterns that are not phone numbers rule 82 indicates that thefollowing common number sequence should never be identified as phonenumbers:

IP-numbers,

date and time formats,

a number with only one parentheses and not both,

appearance of parentheses characters in the subscriber number part of anumber sequence,

ISBN numbers.

The US phone numbers rule 86 allows the specific US format to be pickedup: 1 703 XXX XXXX.

The US tele names rule 86 supports the recognition of US phone numberscontaining letters on the assumption that all numbers begin with 1 800followed by capital letters.

The starting digits rule 88 applies to the leading character of a phonenumber. In most countries which have a leading character, usually zero,that character is always written when the number is written in localformat. For those countries, if the leading character is not present,the number sequence is not a phone number. However in some countries thezero is not always written.

The outputs 90 will now be described. The outputs can be returned eithersynchronously or asynchronously and are in a collection class object 100or an XML file or a low level C++ struct, with the following properties.

The properties of the class displayed in each phone number object areexplained below.

Is mobile is a Boolean property which is false by a default and true iffound in the list of mobile characters. Each mobile carrier is assignedcertain numbers so it is possible to identify whether or not a number isa mobile number by comparing with the assigned numbers.

The fax property 122 is a Boolean property which indicates that a numbercan be used for sending faxes. The number could also be used to makephone calls.

The fax only property 120 indicates that this number can only be used toreceive faxes.

The rate property 118 indicates the rate of the phone call to thisnumber.

A tool tip property 116 is a string with the following syntax:

-   -   call % 1 s using SKYPE in % 2 s (% 3 s/minute),        % 1 s is the phone number (if available the name followed by a        phone number) % 2 s is for country name in which the phone        number is and % 3 s is the SKYPE out rate for that number. This        is a standardised record for the number for the client software        300.

The number to call property 114 is the phone number in the formatrequired by SKYPE to call it.

The number to display property 112 is a localised format of the numberfor display purposes on display 306 so that the user can recognise it.

The position property 110 is to be used for navigation within the text,to represent the location of the phone number. It is in the form of anoffset representing the number of characters from the start of the textto be analysed to locate the phone number. The web toolbar can thenplace the call button on the page.

The type property 108 indicates what kind of number has been found, thatis either a PSTN number (SKYPE out) or a SKYPE name (SKYPE call).

The name property 106 allows the name to be displayed if it isavailable. The default for this option is the same as the number todisplay.

The length property 104 is the length of the number as formatted in thepage.

The verify property 102 is Boolean value indicating whether the phonenumber is verified A verified number can be trusted by the SKYPE callingfunctionality in a much broader sense and can be dialled directlyPartners are invited to specify in a specific html format which digitsequences are indeed numbers and which are not. If such a specific htmlformat is encountered, the number is considered verified.

FIG. 7 is a flow chart illustrating in overview the operation of the PNRcomponents 2. Operations carried out by the web browser 302, the toolbar200 and the PNR component 2 are shown separated by broken lines. At steps1, the web browser is activated in response to a new address beinginserted in the search field 208. The web browser 302 detects the newweb address at step s2 and calls the PNR function at step s3, as well aslaunching the web page at that web address (step s4). Responsive to thefunction call at step s3, the web toolbar PNR component 2 instantiates aPNR object at step s5 and sends the html of the current page to it. PNRdetermines the most likely country of origin for the web page at step s6and then searches the text of the page for any phone numbers at step s7.Step s6 is carried out using the procedures described above to determinethe most likely country. One or many of the procedures can beimplemented until the country has been established with an appropriatedegree of certainty. A user of the PC can override the selection of thecountry manually by using the country code button in the toolbar 200after the parsing is done. Searching of the text in step s7 is doneusing known pattern recognition software to isolate numerical oralphanumeric sequences. Such sequences are then checked to see whetherthey comply with the rules 72. If any such sequences are located, aphone object is populated at step s8 with the properties described withreference to the phone object 100. The populated phone object is thenreturned at step s9 to the toolbar 200. It can be recalled from there bythe software client 300 in order to call the number, or for displaypurposes on the display 306. The web toolbar actually changes the htmlthat the web browser displays for the user—adding the call button 218.

FIG. 8 illustrates a computer system with the “click to call”functionality demonstrated more clearly. The computer system comprises aterminal 400 associated with a keyboard 402 and another user interfacesuch as a mouse 404. It will be appreciated that any user interface canbe used to replace or augment the keyboard 402 and the mouse 404.Reference numerals 200 and 202 denote the explorer toolbar and calltoolbar as before. FIG. 9 also illustrates the country search button,country code button and the address fields also denoted by the samenumerals. P denotes a page of text displayed on a display 306 of theterminal 400. A cursor C is operated by the user interface, such as themouse 404, and in this case is shown located over a recognised phonenumber 216 around which a button 218 has been created. When the useractuates the cursor, for example by clicking the mouse, the phone object100 associated with that recognised number is passed to the clientsoftware 300 in order to instigate a call to the number.

1. A method of recognising a numeric or alphanumeric sequence ofcharacters in a document, said sequence conforming to predeterminedrules, and representing user identifiers for identifying users in acommunications system, the method comprising: identifying a country oforigin of the document; recalling rules relating to the format of saidsequence associated with the determined country of origin: searching thedocument to identify any sequence in the document satisfying saidformat; and returning any such sequence.
 2. A method according to claim1, wherein the document comprises a web page, and the method comprisesthe step of launching web browser to locate a web page on a world widenetwork.
 3. A method according to claim 1, wherein the document isselected from the group comprising a Word document, an email and a PDFfile or any other text source.
 4. A method according to claim 1 or 2,which comprises the step of converting said sequence into a call formatfor the determined country of origin.
 5. A method according to claim 2which comprises the step of marking said sequence in a displayed versionof the page.
 6. A method according to claim 1 or 2, wherein saidsequences represent phone or fax numbers.
 7. A method according to claim5, wherein said sequences represent phone or fax numbers and the step ofmarking comprises associating said phone or fax number with a button ona display, said button being actuatable by a user to instigate a callusing said number.
 8. A method according to claim 1 or 2, wherein thestep of determining the country comprises examining the domain of thelocated page.
 9. A method according to claim 1, 2 or 3, wherein the stepof determining the country comprises examining the language of text onthe page.
 10. A method according to claim 9, which comprises the step ofexamining the language of text on the page by detecting an html languagecode.
 11. A method according to claim 9, wherein the step of examiningthe language of text on the page comprises executing a languagerecogniser component to recognise the language of preselected words inthe text on the page.
 12. A method according to claim 8, wherein thestep of examining the domain of the located page comprises determiningwhether or not it is a shared domain, and if it is a shared domain thenexamining a secondary domain.
 13. A method according to claim 1 or 2,wherein the step of determining the country comprises examining languagesettings of software installed at a user terminal.
 14. A method ofinitiating a communication via a communication network, the methodcomprising: marking in a document at least one sequence representing acommunication identifier, the step of marking comprising associatingsaid identifier with a button displayed to a user, actuating the buttonat a user interface of a user terminal; and executing a client installedat the user terminal to receive said identifier and instigate thecommunication via the communication network using the identifier.
 15. Amethod according to claim 14, which comprises the step of converting thesequence into a call format suitable for making a phone call from thecountry of origin of the document.
 16. A system for recognising anumeric or alphanumeric sequence of characters in a document, saidsequence conforming to predetermined rules and representing useridentifiers for Identifying users in a communications system, the systemcomprising; a component for identifying a country of origin of thedocument; a store holding rules relating to the format of said sequenceassociated with the different countries; a search component arranged tosearch the document to identify any sequence in the document satisfyinga format for the determined country of origin; and a tool forinstantiating an object for returning any such sequence.
 17. A systemaccording to claim 16, which further comprises a web browser arranged tolocate a page on a world wide network, said page constituting saiddocument.
 18. A system according to claim 16 when implemented on a userterminal, the user terminal further comprising a client for executing apeer-to-peer communication using said user identifier.
 19. A systemaccording to claim 18, which comprises a converter arranged to convertsaid sequence into a call format for use by said client in apeer-to-peer communication.
 20. A computer readable medium comprisingcomputer code components which, when executed by a computer into whichthe computer medium is installed, implement the following method steps:identifying a country of origin of a document; recalling rules relatingto the format of a sequence of numeric or alphanumeric charactersassociated with the determined country of origin; searching the documentto identify any sequence in the document satisfying said format; andreturning any such sequence.
 21. A method of effecting a voicecommunication between user terminals over a communication network, themethod comprising: displaying to a user at a user interface a menu ofcountry options; selecting a country of a destination of thecommunication from said country options; receiving a number in localform; recalling formatting rules for the destination country; appendingto the number a country prefix for the country of destination inaccordance with the formatting rules to generate a formatted number, andsupplying the formatted number to a client installed at the userterminal for effecting the voice communication using the formattednumber.
 22. A method according to claim 21, wherein the step ofdisplaying the menu comprises displaying a map on which each continentprovides a respective menu of country options of that continent.